This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Recent findings from The Sood laboratory indicate that platelets may play an important role in ovarian cancer growth and metastasis. We hypothesize that platelet ultra-structural changes reflect alterations in platelet function that facilitate disease progression in ovarian cancer patients. Thus, in order to gain better understanding of ultra-structural changes that may denote platelet pathobiology in ovarian cancer, we propose comparing platelets isolated from the peripheral blood of healthy donors to those from newly diagnosed ovarian cancer patients at the ultrastructural level using electron cryomicroscopy. Platelet electron microscopy is now used clinically to help determine if patients have an intrinsic platelet abnormality related to bleeding risk. The inherent advantages of electron cryomicroscopy make it preferable for the current investigation because cryo-EM would afford improved sample preservation.